Some of Us Are Drowning
by Lost in Ashes
Summary: Most mermaids are terrified or disgusted by the mere mention of human beings. Sherlock Holmes isn't most mermaids.
1. Chapter 1

"Men were deceivers ever  
One foot in sea and one on shore  
To one thing constant never,"  
- William Shakespeare

Chapter I

Sherlock was only nine years old when he began to suspect his life would be unbearably dull. It was a simple question of mathematics. Mermaids lived, on average, between five and seven hundred years. Seven hundred years, swimming the same paths, having the same conversations, occasionally composing a new song to break the monotony. Sherlock felt nauseous just thinking about it.

His teachers told him that he'd be happier if he made more of an effort to make friends. A lot of people wanted to be friends with Sherlock. He was royalty, after all. But talking to other children around him only seemed to make the boredom yawn wider in his chest. All they wanted to do was shine their tails and brush their hair and discuss who was the most beautiful or who had the best singing voice (a pointless exercise as the answer to both questions was, quite clearly, _Sherlock_). Sherlock got into the habit of swimming off and watching the fish instead. They were even stupider than mermaids, their brains slow and basic in the extreme, but there was a kind of satisfaction in puzzling out the rhythms of their lives, the patterns in which they swam, how they lived and died, ate and were eaten. On weekends he swam further afield, and found himself a pod of dolphins to swim with. Dolphins were quicker, smarter, more cunning than fish but they always wanted to play the same games and Sherlock got bored again.

By the time he was ten years old, Sherlock had charted every square mile of the Inner Queendom, observed and noted the movement and behaviour of every different species within it. When he came to the realisation that there really wasn't any new to see, not anything at all, Sherlock curled up on a knoll of seaweed and cried. That was where his brother Mycroft found him some hours later.

Mycroft looked down at his little brother and sighed. Mycroft sighed a lot, it was his way of reminding everyone how much more clever and important and responsible he was than anyone else. He especially liked to do it when speaking to Sherlock.

"Go away, Mycroft." Sherlock said, as imperiously as he could manage with a face still flushed from sobbing.

Mycroft didn't reply to this, merely flicked his long tail and drifted over so he could float by Sherlock's side."If you like I could speak to Mummy about assigning you a small role in the Governance." he said. "You are young for it but time does pass more easily when you have duties to fill it."

"You'd like that, wouldn't you?" Sherlock said. "Making me your errand boy. Well, I won't do it. It's all stupid anyway." He curled up his hands into fists, and crushed them against his eyes, hard enough that spot appeared in front of his eyes.

"I know." Mycroft said.

Sherlock looked at him in surprise. Usually Mycroft couldn't stop talking about how Great and Important and Worthy his work for the Queendom was.

"When I was your age, I felt the same way." Mycroft said. "Most people aren't as clever as we are."

Sherlock snorted at the understatement.

"It does get easier, as you grow older. You find interests in the world, in your work…"

"Really?"

Mycroft smiled, thinly. "Maybe Governance isn't your destiny. But you will find something, Sherlock."

"Maybe I'll just go and get myself eaten by a shark."

Mycroft glanced at him, frowning. "That isn't amusing."

"I wasn't joking."

Mycroft turned his tail lightly, flipping onto his back. He looked upwards through the water. "You know – I shouldn't…." he trailed off, frowning.

Sherlock was immediately interested. "What?"

"You have made a study of almost every species in this Queendom. Have you ever thought to look above the surface?"

"You mean gulls and albatrosses?" Sherlock asked, disappointed.

"I mean Humans." Mycroft said quietly.

Sherlock sat up.

"I thought I wasn't allowed to – "

"You aren't." said Mycroft. "You're far too young to go near the shipping lanes. But there are, there have been – Findings. Objects from the world above that came down to us, in wrecks or by accident. There are those who make quite a study of it. When I was your age I went through a phase when I was rather fascinated with it myself. "

"Will you show me?" Sherlock asked, eager in spite of himself.

Mycroft hesitated, then sighed. "You'll need a special security clearance. It's a very great responsibility. I wouldn't offer it unless I –"

But Sherlock had shot up off the ground and was turning a loop in the water grinning..

"You _will_ let me."

"Yes, yes." Mycroft smiled at his brother's enthusiasm. "But – listen, Sherlock. I must warn you– there are dangers to the study of Humanity. You must not allow yourself to be seduced. Do not forget who you are."

Sherlock rolled his eyes. "Of course not."

"Hmm. Well, come along then, Sherlock. It's almost time for the Banquet and Mummy will be waiting."

"But will you –"

"I'll take you to the Warehouse." Mycroft promised. "Later. But first, make yourself presentable. The Ambassador will scream if you go down to dinner looking like that."

* * *

If Sentinel Lestrade had previously thought Prince Mycroft seemed a bit mad, the morning's events had confirmed the suspicion. The man had strolled in to his office that morning with a distant smile and casually announced his intention to introduce a ten year old child to the highly classified and exceedingly dangerous work of the Human Squad. If he was an ordinary person they'd be taking the man down to the Sanatorium to be evaluated.

But of course, he wasn't an ordinary person, he was a Prince, and they all had to do what they were told.

"Is he _serious_?" His second in command, Donovan, made a face not unlike the back end of a walrus when he passed on the news.

"It seems so. I think the kid just has a few questions – he's the curious sort. You know? We'll just give him a quick tour, chat to him for a bit. I'm sure he'll get bored and wander off after a while." Lestrade tried to sound reassuring and not at all like he thought the man who was second in command of the whole Queendom was having a nervous breakdown.

"I hope so." Donovan snarled. "I didn't sign up to be a babysitter."

"I hear that kid's pretty weird." Anderson swam over. "My cousin teaches at his school. Says he never talks to any of the other children, just wanders off and bothers the fish."

"Well, that's royalty for you." Donovan said. "Too good for anyone else."

Lestrade cleared his throat rebukingly. "Now, now."

"He has a lovely voice." Mollysa, their Remains Expert said from behind him. Lestrade tried not to jump. Mollysa was such a quiet little thing, he tended to forget she was there.  
"I went to a banquet at the palace, and they had him sing. He's really – exceptional. I don't think I've ever heard anything like it."

"That could be useful, if he really _does_ have an interest in working with Humans." Lestrade said thoughtfully.

"He is _far_ too young for Siren training." Donovan said.

"I know," Lestrade shrugged, "No harm in planning ahead though, is there? Come on, Donovan, make nice. You never know when it might pay off."  
Donovan pursed her lips.

* * *

In fact, introducing Prince Sherlock to the Human Warehouse turned out to have very little in common with babysitting and rather a lot on common with sitting an unscheduled and extremely stress inducing inspection. The young Prince had questions about everything, and fixed Lestrade's team with an icy stare when they he was not answered adequately and in full. Lestrade hadn't felt so nervous since his Advanced Human Culture assessment back when he was training to join the Guard.

"What is this?" Sherlock picked up another item from the shelves.

"_Careful_," hissed Donovan behind him. Lestrade shot her a glance. "Your Highness," she added grudgingly.

"We believe, some sort of weapon." Lestrade explained. "Or possibly a surgical tool."

"Hmm." Sherlock looked down his nose at it. "The latter is more likely, I'd say. Look at the rotating mechanism – it must have a very specific purpose. And while it could certainly do some damage, it is hardly something one would reach for in the heat of the moment." He held it up to the light, pale eyes glowing with interest. "Fascinating. May I keep it?"  
Donovan made an irritated noise in the back of her throat.

"Of course," Lestrade said.

The Prince didn't bother to say thank you.

Lestrade was wrong about Prince Sherlock becoming bored. He very quickly seemed to make the Warehouse his second home, spending every spare hour he had wandering around the long corridors, picking out items and examining them with a ferocious interest. As they soon discovered, he had quite a gift for analysis. Donovan was almost apoplectic with fury when Sherlock took one of their oldest finds (a circular metal box, found among the clothes of a drowned mariner) apart, until he explained that he had figured out the mechanism. He gathered the disgruntled team around him and explained how a series of cogs and screws operated to keep a little stick rotating upon an axis under a glass face.  
"I think it's a timekeeping device." Sherlock said, his pale face ablaze with interest. "Some way of marking events as they pass."

"How can you possibly know that?" Anderson's eyebrows were raised.

Sherlock looked back at him disbelievingly. "What is it like in your tiny little minds? Look, these are numerals, _clearly_even you would recognise them. It isn't designed to interact with its environment, it runs on its own cycle: and if you look around there are at least two other devices in this warehouse designed in the same way, even though they originate from different ships. They measure a _constant_, something that follows the same pattern in different places, and in different ages. And it's a practical tool, just look at the scratches on it – this has been kept close, used, constantly. What could they be measuring, what would they need to measure in this way? Humans live above the surface, they don't have the pressures of the tide around them all the time, and looking at the sun is too imprecise for complex arrangements- they had to find their own way of measuring time. With _this_. It's _obvious_."

Lestrade had to admit it was an impressive theory. Certainly more imaginative than anything any of his team of analysts could come up with. He had a feeling the same thought had struck his team, and that they were not enjoying the idea.

"He's a _freak_," Anderson spat out later, once Sherlock had left touting another of his supposedly classified trophies. "Have you seen that kid's face when he touches the Human objects? He practically glows. Its bordering on obscene."

"It gives me the creeps." Donovan agreed. "The gods only know where the kid'll end up. You know, he asked me about the Ithillya Rain? I told him I'd been there, that I'd seen the place the ship went down. It's the kind of thing any normal child would have nightmares about. He was _excited_."

"He's just curious." Lestrade said firmly. "He's still young. He'll understand the emotional aspect of what we do better, with time."

Privately, though, Lestrade did worry that the young Prince didn't display any of the healthy disgust Mermaids usually felt when dealing with Humankind. On the contrary he seemed rather dangerously enthralled with them. Lestrade worried for the boy. The more time he spent with the Prince the more it became apparent how isolated the child was. The boy had no father to speak of, no friends and his mother was too busy ruling the Queendom to attend to him. The only person who seemed to take an interest in Sherlock's development was Prince Mycroft, and his idea of care mainly seemed to involve pointing Sherlock in the direction of a dangerous hobby and letting him get on with it. It was small wonder that the kid had a warped view of what was normal.

Perhaps it was time Lestrade had a word with the boy.

"You know, your Highness." He began, swimming over to hover beside the boy as he examined a peculiar piece of carved wood. "You do have quite the gift for analysis."

"I know. Obviously." Sherlock ran his fingers over a carved S shaped hole in the wood. "What does it_mean_?" he muttered to himself.

"But I was wondering whether you knew why we do what we do. About the history of Mermaids and Humans."

Sherlock looked up, frowning.

"I don't know what they teach you in school."

"Not much." Sherlock said. "And it's mostly wrong anyway. I told my teacher but she wouldn't listen to me."

"Right." Lestrade said, feeling a flash of sympathy for Sherlock's teacher, whoever she might be. "Well. Humans are – as you know, we used to live side by side more or less peaceably, until a few centuries ago. We didn't have much to do with them, of course, but they didn't harm us, nor we them. But then their numbers increased and they began to pump out dirt into the seas. It became dangerous for mermaids to stray too close to the shores, because there was poison in the water. Even eating the fish from the coastlines could make you sick. And the Humans became greedy, pulling more and more fish out of the ocean, several Queendoms experienced famine. And then, there came the Black Rains – "

"I know about that."

"With all due respect, Your Highness." Lestrade said gently. "I don't think you do. I was there a couple of weeks after one of them, in the Antagondom Queendom. The water had gone black, blotted out the sun. Particles of darkness drifting down through the water, everywhere – those in the worst hit areas suffocated within minutes, others, further away, died more slowly. Some people swam to the surface only to find themselves covered with the stuff, coating their skin and blackening their hair, we couldn't get them clean…. Hundreds of mermaids had to leave their homes behind, the crops were ruined, there was famine…."

Sherlock had put down the instrument now and was listening, mouth half open.

"And then, there was Atlantium. No one even knows what happened there. There was a blast of light, a shiver in the water that mermaids felt from here, and everything within leagues of the Queendom just died. The rocks in that area still glow."

Sherlock shivered, a faint flush on his cheeks.

"I don't mean to scare you." Lestrade said kindly. "But if you work with us, it is important that you know these things."

"I'm not scared." Sherlock was pressing his fingers to his lips, obviously deep in thought. "I didn't know they possessed so much _power_."

"Yes, well," said Lestrade, a little unnerved. "You do need to know what you are dealing with."

All of a sudden Sherlock sprang upwards, his scrawny body pulling itself straight.

"Mycroft." He said.

"What?"

Sherlock's eyes shone with the light of a new discovery. "He's been lying to me – to you too, probably."

"I'm sorry," said Lestrade. "I don't follow."

"Never mind." Sherlock snapped. "I need to see my brother."

And he swam away without a backward glance.

Lestrade looked after him, mystified. _Well. That could have gone better._

* * *

Mycroft looked at his little brother wearily. How exactly he'd managed to bypass three sets of Guards and a locked door and find his way into Mycroft's office he didn't know. He would have to re-evaluate his security measures. Again.

"I want to see the scrolls."

"What scrolls?"

"The _secret_ scrolls." Sherlock said. "I know they exist. You wouldn't let such a rampant threat to national security exist without having more information than this. There is more – I want all the information you haven't seen fit to share it with Lestrade and his troupe of floating morons."

"It's always nice to hear that you've been making friends."

"_My_croft."

"You are ten years old. If these scrolls do exist, why on earth would I share them with you?"

"I'm almost eleven. And I will find out what they contain eventually. There will be less effort on your part and considerably less embarrassment if you let me see them now."

Mycroft fought very hard not to smile. His little brother, ten years old and already sharper and more determined than half the Queendom put together. While he wouldn't have liked it to be generally known, and certainly not by Sherlock, Mycroft loved his little brother quite inordinately. Before Sherlock had been born Mycroft had been quite alone in the world. Sherlock was the only one, apart from their mother, who had a mind like Mycroft's, bright and brilliant and utterly unable to find satisfaction in any of the banalities with which most Mermaids occupied their time.

"Very well," he said as coldly as he could manage.

Sherlock's eyes widened. "Really?"

"As you say, you'll find your way to it eventually, and I have no desire to spend the next few months fending off your attempts at espionage."

Sherlock's smile was so wide it looked like it might actually cut his face in two. Mycroft told himself he is making the right decision. He had to be.

* * *

"What is Hudson?"

"Hmm?"

Mycroft was preparing himself for a very important banquet. It was of paramount importance that he looked his best. He wound a shell bracelet around his forearm, leaning back to admire the effect. Not quite the correct shade of blue, he feared. He looked again at his collection spread out on the shelf. Perhaps the coral.

"Hudson. It's mentioned in the scrolls as a source, several times, but there's no explanation of what it is."

"Ah." Mycroft cast a glance back at his little brother, who had ensconced himself in his sleeping hammock and was watching him through narrowed eyes.

"You might as well tell me." Sherlock whined at him. "I know practically everything else."

Mycroft sighed, and wondered yet again if he ought to have allowed Sherlock's obsession to progress to this point. But then, what choice did he have? It had been the best way to forestall Sherlock from going down a worse path. At least he was spending his days in a way that might one day benefit the Queendom, instead of swimming off into the path of predators or under the helms of ships….

"Hudson isn't a what. It's a who."

Sherlock sat up at this. "A Human?"

"No." The pink torc made Mycroft's arm look uncomfortably chubby. Perhaps he should consider another diet.

Sherlock slumped slightly. "What then?"

"A merwoman. She was taken prisoner by Humans some four hundred years ago. Unpleasant business. I believe they kept her in a cage, treated her as some sort of circus exhibit. At any rate she escaped, and managed to return to her own kind. We interviewed her extensively. She is the source of much of our most reliable information about Human culture."

"She's still alive?"

"I believe so."

Sherlock sat bolt upright, his face pale. "I want to meet her."

Mycroft smiled thinly. "No doubt."

"_Please_, Mycroft."

Mycroft sighed heavily, and waited for a few beats, watching Sherlock's face grow taut with tension.

"First, I'm going to need you to do something for me."

"What?" Sherlock frowned suspiciously.

"Your voice coach thinks you show great promise."

"Oh." Sherlock said unenthusiastically, "That."

"I want you to undertake training to be a Siren. I have written to Ithilliya, they are sending their very best Siren to teach you."

"You've employed Irene the Adler?" It seemed even Sherlock couldn't help but sound a little impressed.

"Like I said, Sherlock, I believe you show a great deal of potential. It would be quite something for the Queendom to have a first class Siren at its disposal. It will require a great deal of commitment on your part, however. I need your assurance that you will take this seriously. It would not do to be made a fool of in front of the Ithilliyans."

Sherlock tilted his head speculatively, watching Mycroft. He was waiting to give an answer, building the tension in the room, just as Mycroft would have done. Mycroft felt a rush of pride. If Sherlock could learn to manipulate, he could do anything.

"You should wear the purple shells." Sherlock said. "Your hair is by far your finest feature. Purple brings out the subtler shades, makes it appear to shine._And_ its slimming." He got out of the hammock and swam towards Mycroft. Their eyes met in the mirror.

"I will work at Siren training, as diligently as you could possibly desire," Sherlock promised. "_If_ you allow me to meet Hudson."

Mycroft smiled. "I will send you round a briefing tomorrow morning."

Sherlock nodded and drifted out of the room. Mycroft picked up the purple armlet. It _did_ suit. Sherlock was right, as usual.


	2. Chapter 2

Chapter II

Hudson's real name was Una. She lived alone in a sea cave at the far edge of the Inner Queendom - it wasn't easy to find. The nearest village was miles away, and the coral formations in which Hudson apparently made her home were warren-like. Sherlock had to stop and consult the map Mycroft had given him several times. He was close to giving up and turning back when a voice called down to him from among a thick patch of seaweed.

"Are you lost, young man?"

An old woman, long grey hair billowing in the current.

"No." Sherlock looked at her closely. "I don't think so. Are you Una?"

The woman drifted closer, eyes narrowed.

"Some people call me that."

"Others call you Hudson."

The old woman blinked, and smiled.

"You must be Mycroft's little brother."

It was Sherlock's turn to look surprised. "He told you I was coming?"

"No. But you have quite the family resemblance."

"I don't look like Mycroft."

"It's the expression. You look like you'd like to tear the world apart to find out what it is made of." Una tilted her head at him and gave him a smile. "You'd better come in."

Sherlock followed her into the mouth of the cave. It was surprisingly vast, and lit by luminescent jellyfish hung on a string. Sherlock looked around, taking it all in: the sleeping hammock, the cooking surface, a shelf full of scrolls. An old anchor rusted in the corner. Decoration, presumably.

Hudson swam to the corner of the cave, moving a slab of rock to one side. Sherlock felt a breath of heat emanating from it.

"It's a shaft – goes down towards the earth's middle." Hudson explained, at Sherlock's confused look. "Humans usually eat their food warm and it became rather a habit with me. Here you are, dear."

She pulled something up out of the pit and brings it over to Sherlock. It was a flattened cake of some sort, made of seaweed. Sherlock took a bite. Heat flooded Sherlock's mouth like an embrace, the cake soft and sweet.

"It's good." Sherlock said, in surprise.

Hudson smiled proudly. "My own recipe."

"Does all Human food taste like this?"

"Not quite like this," she said. "Humans never use enough salt. So," She sat down in front of him, smiling brightly. "What is it you want to know?"

Sherlock wiped his mouth, and considered. "I want to know everything."

Hudson laughed, her long nailed fingers touching lightly at her chest. "Oh, you are like your brother, aren't you? Well, _everything_ might take a while."

Sherlock frowned at her, unimpressed by her levity. "Tell me what happened." He leaned forward intently. "Start from the beginning and omit as few details as possible."

Una raised her eyebrows a little but she was still smiling.

"Oh, well then. Let's see. It happened when I was a girl – not much older than you are now really. We lived nearer the land in those days – it was before the Humans started pumping all that nonsense into the oceans, and people weren't so funny about the idea of approaching them. My friends and I would play a game… we'd swim up to the coast and see if we could spy a Human. We discovered a little inlet where the water was deep enough for us to hide, and, well," Una's dark eyes shone with mischief.

"Some of the Human boys from the nearby village used to swim there. We never went near them, of course – just looked. There was one in particular, he was so beautiful. So brown skinned and strong and smooth looking – the way he moved through the water, with those legs of his ..." Una cleared her throat, seemingly remembering that she was talking to an eleven year old. Sherlock smiled encouragingly.

"I found out that he liked to swim in the evenings too, by himself. So I went back alone, to watch him. I wanted to have something of him to myself, without the other girls chattering in my ear. I suppose I wasn't as careful as I should have been. I got distracted. I was drifting through the water, waiting for him, when I found myself caught. It was one of those awful fishing nets that had been strung out under the water. I struggled as hard as I could but I couldn't get free."

A faint frown line appeared between Una's eyebrows.

"After a while the Humans came – a group of men. You should have seen their faces when they found me! So surprised! If I hadn't been so afraid by then I think it would have been amusing. They didn't seem to know what to do with me at first, and some of them seemed rather afraid of me. I tried holding out my hands to them and begging to be set free but they didn't understand. In the end they hauled me out of the water and carried me back to one of their houses. I stayed there for a couple of days, in a trough that they used to give their animals water."

"Eventually they loaded me into a cart and took me to the next town, where there was some kind of market. They sold me to a man in a bright red coat, a circus owner but the name of Billy Hudson. I believe quite a large sum of money changed hands. I became part of a travelling entertainment troupe. It was very strange at first – being carted around from place to place and having Humans stare at me. But I made friends. The son of the circus owner – a nice boy, by the name of Eric – he taught me to speak their language, even to read a little. And then there was a woman with a beard, and a pair of twins who's been born joined together at one shoulder, a man who had never grown to be any larger than a child. None of them thought it was too strange that I had a tail."

"I was in that circus for nearly seventy years. The first owner died and Eric inherited me. He was close to retirement that wrong sort of people began to take an interest in us. A scholarly gentleman with ink all over his fingers asked Eric if he could buy me – of course, Eric said no. But as we went away, he overheard the gentleman saying I ought to be dissected and examined in the interests of science. I spoke to Eric for a long time that night and we agreed that it was quite time I went home, to my own people. Eric took me down to the shore and lifted me into the water. And then – I swam away." For a moment Una looked away, expression soft, regretful.

Sherlock leant forward, rapt. He had a thousand questions, far too many to be contained in one single visit, he suspected, so he stuck to the one that was most important.

"You can speak Human?"

"I can speak English." Una said. "It's one Human language."

"Can you teach me?"

Una looked at him, consideringly. "Well. If you like. You'll have to come up to my cave for lessons - I'm too old to go gadding around the Queendom."

"How soon can we begin?"

Una laughed. "Well. Tomorrow's my gardening day, and the day after that my sister's coming to visit. How about three days from now?"

"Agreed."

"You'd better get going." Una said gently. "You only have a couple of hours before it gets dark. Your mother won't be happy if you get lost."

Sherlock didn't point out that his mother probably wouldn't notice.

"I'll see you in three days, then?" he said anxiously.

"I'll look forward to it. It'll nice to have a young face around the place." Una ruffled his hair. "Careful about how you go, won't you?"

"Of course."

Sherlock found himself oddly reluctant to leave the warmth of the cave, and perhaps it showed in his face, because Una's expression softened.

"Here." She wrapped one of her cakes up in a sheet of fresh seaweed and handed it to Sherlock. "Come back soon."

She dropped a light kiss on the top of Sherlock's forehead.

As Sherlock swam away, he held the warm cakes against his chest, trying not to shiver in the chill of the darkening water.

* * *

Irene the Adler arrived a week later. Suprisingly for someone whose fame was spoken on throughout the Seven Queendoms, Irene travelled with very little in the way of an entourage and almost no luggage. Sherlock watched from where he'd hidden himself in a cupboard in the corner of the Throne Room as Mycroft ushered Irene and her assistant into the Palace. She didn't look like anything extraordinary – a slim woman with dark hair and a heart shaped face. The only thing that stood out about her was her mouth: it had been painted a piercing shade of blood red, standing out starkly against her pale skin.

"You will, of course, be given the very best rooms we have to offer." Mycroft said.

"Naturally." Irene said coolly. "And the terms we have agreed on…."

"Will remain unchanged, of course. I'd like to say the cost of my brother's education won't blow too much of a hole in the wealth of the nation, but I'm afraid I'd be lying." Mycroft had that wry half-amused tone he always used when talking about Sherlock, as if he was speaking about a particularly troublesome pet. It made Sherlock scowl.

"He must be a talented boy."

"We believe so."

"Not too good at hiding, however." Irene turned abruptly and her bright blue eyes seemed to be staring directly into Sherlock's.

It wasn't possible. He'd hidden himself completely. She had to be bluffing. Sherlock resolved to sit tight and let them move on.

Mycroft followed Irene's gaze. "Is someone there?"

Sherlock remained silent.

Irene tossed her hair over one shoulder, and opened her mouth. The sound that came out seemed to make the whole room reverberate and Sherlock's heart thump uncomfortably in his chest. The melody that she sang was unfamiliar, strangely haunting, and it made the room around Sherlock seem to blur. There was too much music in the air, it had a strange density, blocking out thought, reason, everything – it was de_light_ful. Before he knew it Sherlock was on his feet, reaching out his arms with eyes closed, as if he could absorb more of the music by laying open his bare arms to it.

Abruptly the sound faded leaving Sherlock standing in the middle of the Throne Room, Irene and Mycroft both staring down at him. Irene's red mouth was stretched wide in triumph, showing teeth.

"Well, well. I've never seen Sherlock so obedient." Mycroft looked at the Siren, eyebrows raised. "That is a potent Song."

"It's difficult to Sing well enough to bewitch a Mermaid. Only the most powerful songs will do it." She hadn't taken her eyes off Sherlock all the time he was talking to Mycroft. "This is my pupil?"

"He is."

"What do they call you, child?"

He wouldn't answer her. He wouldn't. His mouth seemed to open of its own accord.

"Prince Sherlock of Holmes. And I'm not a child." Sherlock tried to sound defiant but somehow it came out breathless.

"Hmm. Very well, your Highness. I will see you at 8 o clock tomorrow morning, in my suite. I take it I have a suite?"

"Well, yes..." Mycroft began.

"Don't be late." Irene cut across him, turning away sharply with a dismissive flick of her tail she left, a bemused looking Mycroft following in her wake.

* * *

"Sing for me." Irene demanded as soon as Sherlock entered her room the next morning. Mycroft had certainly gone all out to impress the Ithillyian Siren. The room was beautifully decorated with ornately carved corals, luminous and brightly coloured fish kept in cages dangling from the ceiling. A bowl full of anenomes stood on the central table, scarlet heads dancing in the faint current.

"What do you want me to sing?" Sherlock asked. Irene waved her hand negligently. She was lying in her hammock, her posture not unlike one of the old Sea Empresses receiving tribute. She certainly wasn't like any teacher Sherlock had ever had.

Sherlock straightened his back and began to sing. He chose the Anyagian's Lament, a tragic ballad concerning a doomed love affair between two rival Princesses. Last time he'd performed it, at one of Mummy's banquets, he'd had half the room in tears.

Irene stopped him after two phrases.

"Uninteresting. Is that the best you can do?"

Sherlock stared at her. She smiled a little.

"Oh dear. You _do_ have a lot to learn, don't you? Being a Siren isn't just about being able to carry a tune, my lovely. Any fool can do that. You need to observe. Feel out the edges of the world around you, find out your audience's thoughts, their hopes, interests, insecurities. Only then will you be able to change them. Watch me."

Irene Adler threw back her head and began to sing. It was the Anyagian's Lament again, only this time the words seems to cut somehow, pulling at something deep inside of Sherlock and leaving him aching and raw. Sherlock bit his lip hard to prevent the tears rising to his eyes, because he never cried, he never did, but suddenly all he could think about was how very alone he was. There was no one in the world like him, except Mycroft, and he didn't even care really. The world was too large, too empty, too horrible, he didn't think he could bear it. And then, just as the feeling became more than Sherlock could stand, the song changed, a subtle warmth interjected into Irene's Adler's beautifully distinct syllables. Sherlock found himself moving forward in spite himself. She was so beautiful, his teacher. He wanted to be near her, to touch her. He wanted to kneel at her feet…

Abruptly the song was cut short. Irene Adler was looking down at him, eyebrows raised sarcastically but there was a gleam of what might have been sympathy in her eyes.

"You see?" she asked.

"Yes." Sherlock's voice sounded oddly scratchy to his own ears. His knees ached. "Yes, I see."

"Very well. Stand up and try again."

* * *

Time passed swiftly from then on. Lessons with Irene were taxing in a way nothing in Sherlock's life had been before. But he was learning. Within a month he'd already been able to attain a degree of control over some of the stupider breeds of fish. He felt a rush of power as he watched a school of anchovy swim in a criss-crossed, dizzyingly intricate pattern, their every movement dictated by Sherlock's will.

Sherlock still managed to find the time to go and visit Una at least three times a week. His English lessons were progressing apace, and he was finding out more and more about Human culture and behaviour. It didn't leave a lot of time for schoolwork, but Sherlock was unconcerned by that. School was largely pointless anyway.

One day, when Sherlock was about a year into his training with Irene, Lestrade appeared unexpectedly in Irene's suite where Sherlock was attempting to Sing to a crab (it kept scuttling away from him).

"What have you found?" Sherlock asked him.

Since Sherlock had become too busy to visit the Warehouse, Lestrade had got into the habit of bringing some of the more mysterious finds to Sherlock, since his employees had all the imagination of a seal that had been dead for three weeks. He'd never come to Sherlock while he was studying before, though.

Lestrade cleared his throat, glanced at Irene Adler, blushed, and then glanced away. Unlike the women of Holmes, Irene and her assistant Kate left their chests bare, their long flowing hair their only cover. Sherlock couldn't help smirking at Lestrade's obvious confusion.

"Did you want to speak to my pupil?" Irene asked him in clear ringing tones.

"Er – actually I was hoping _you_could help us." Lestrade looked at Irene.

Irene cocked her head in interest. "Oh?"

"A Human ship has strayed out of its usual path, and the way its heading it will disrupt the seal migration."

Sherlock looked up interestedly. Seal herding was one of the more lucrative industries in Holmes, it was no wonder Lestrade was upset by this development.

"And you want me to persuade them to redirect their vessel?"

"If you would."

"Of course." Irene drew herself up. "Sherlock, get ready."

"You, er- you aren't planning to bring the Prince…"

"Of course I am. He has never witnessed Human Singing. It will be very beneficial for him."

"It's too dangerous. He's only a child. If one of the Humans were to get hold of him….."

Irene laughed lightly. "Sentinel Lestrade, do you doubt my abilities?"

"Not at all, but-"

"Believe me, while I am Singing the Humans will be incapable of doing anything other than what I wish them to do. And that includes bothering our little Prince."

Lestrade opened his mouth to objects, and Irene made a humming noise in her throat. Lestrade's eyes glazed over slightly and he nodded. "All right then."

Sherlock made himself ready, head buzzing with excitement. He was going to see a real Human ship. Perhaps, if he was lucky, a real live _Human_.

* * *

Lestrade and his crew took up position a few miles ahead of the ships current trajectory, intent on intercepting it. Sherlock enjoyed the feeling of holding his head above the surface of the water, noting the openness of the sky above, the feeling of cool wind buffeting his hair. Lestrade's team were tense with anticipation, spears at the ready - should Irene's Singing fail, they were ready to try to sink the ship by hand. Irene on the other hand looked perfectly relaxed, and even took the time to comb her fingers through her long hair as she waited (Donovan shot her an irritated glance.)

Eventually they saw the ship, a dark point looming on the horizon. Donovan sucked in her breath through her teeth and readjusted her grip on her spear. Lestrade shifted in the water, as if trying to block Sherlock from its view.

"Ready?" Irene asked.

Lestrade shot Irene a dubious glance. "If you think you can manage it from this distance."

Irene only smiled, pushed her hair back from her shoulders and began to Sing.

As the first clear sweet notes hit the air a shudder ran though the team of Guards. Sherlock watched as Lestrade's shoulders subtly relaxed, as Donovan's eyes lost their wary look and drifted shut. As for Sherlock, the same addictive sensation of lightness overtook him, making his blood seem to sing. He found himself wanting to laugh, but choked the sensation down. He didn't want to make a fool of himself with Lestrade's team looking on.

"Can we move a bit closer?" he asked Irene.

"There's no need." said Lestrade. "They seem to be turning around already." He huffed a half disbelieving laugh. "You stopped them short at half a League's distance. Incredible."

"If I get a little closer," Irene said persuasively. "I can plant the idea in the captain's head that these are dangerous waters. Prevent them attempting to come here again."

Irene's eyes met Sherlock's and gleamed conspiratorially. Sherlock tried and failed to control his grin.

"All -allright." Lestrade said dazedly, the song clearly still having an effect.

Irene began to swim towards the ship and Sherlock followed her. As they drew closer, Sherlock drew in his breath with excitement, eyes scanning the ship, trying to calculate the details of its construction, the speed at which it moved, to quantify the lives hidden inside that vast metal belly.

Once they were close enough for Sherlock to make out every bump and seam on the boats exterior Irene stopped short, one soft hand curling around Sherlock's wrist.

"This is close enough."

Sherlock wanted to shake her off and move closer, to see more of the ship and the people inside it. But he is caught by the song, limbs suddenly heavy and unwilling to move away from her. Beautiful teacher, lovely, lovely Irene.

"You don't need to be able to see them." Irene said. "Reach out with your mind. Feel the echoes left by the song, the spaces that are left by it. Then you will know everything about them."

Sherlock tried to do as she said, closing his eyes and listening. He tried to track the way the sound rippled through the air, the places where it moved freely, the places where it was absorbed or reflected by objects in the way. The sound became harder when it made contact with the metal sides of the boat, bore the imprint of nails, the impression of seams soldered together. More distantly he could feel something else - a softer collision of sound, coloured by thought, emotion, desire - a living being communicating with the song, feeding on it and breathing it back, subtly distorted. Sherlock concentrated hard, trying to picture the man Irene was bewitching but the effort was too much, and the picture slipped away from him leaving him gasping and confused. He opened his eyes and saw Irene watching him. The look in her eyes surprised him. It seemed oddly haunted, as if she was afraid of what she saw. Abruptly, she closed her mouth and the song stopped.

"They won't be back." she said.

"You shouldn't have taken him so close." Lestrade had appeared behind them, frowning. The song's spell had clearly been broken, for now, at least.

"He was perfectly safe. I had them under complete control."

"Even so." Lestrade was watching Sherlock with a troubled expression.

"I was fine." Sherlock snapped. He wasn't sure why exactly but he had started shivering, the tight sensation his chest growing oddly painful.

"Don't you people ever go closer?" he said aloud. "You have the opportunity to learn so much more about Humankind. Don't tell me you spend all your time lurking at the edges like this."

"We avoid direct contact when we can. Sometimes, yes, we have to go closer, if a ship had to be moved or even sunk, but that's only in extreme circumstances. This isn't a game, Your Highness."

"But you could l-learn so much more about them if you did! It's – it's p-pure cowardice." Sherlock's looked defiantly at Lestrade, ignoring the way the increasingly violent shivers were chattering the teeth in his head.

Lestrade raised his eyebrows. "If you say so, Sire." He looked at Irene, a very cold expression in his eyes. "That boy needs to be taken back home, wouldn't you say? He looks ill."

Irene looked at him quizzically. Sherlock tried to hold himself still under her gaze but the shaking seems to have got worse. "Hmmm. Reaction to prolonged Singing. The musically gifted are often more sensitive to it. I wouldn't worry, I've done it to my friends plenty of times. He'll be all right soon enough."

"I should hope so. Here, Sire." Lestrade pulled an amulet from somewhere and put it around Sherlock's neck, casting a heating spell. A flood of warmth seemed to envelop Sherlock.

"Good for shock."

"I'm f-fine I don't n-need anything."

"Course not." Lestrade smiled at him. "But I think some my team want to see the picture. Prince Sherlock being Charmed."

Sherlock scowled. He hated magic.

"I told you, he's fine." Irene sounded bored. "Come along, Prince, I'll take you home."

Sherlock was still a little queasy when he got into his hammock that night, so he wrapped his blanket tight around himself, picturing the ship he'd seen again and trying to commit every detail to memory. It didn't yield much. There had to be a way to get closer, he thought, a way to really see the Humans. Though, now that he thought about it, any information gained from the vantage point of the Sea was going to be limited. If only he could find himself some way to observe them in their natural habitat. Of course, he'd never be allowed to visit the Shoreline. But maybe, if he was very clever….

Sherlock drifted off to sleep, the beginnings of a plan forming in his mind.


	3. Chapter 3

A/N: For clarity's sake because a couple of people have asked, I should specify the pairings in this fic will be John/Sherlock and John/Mary. Thanks to those who have left comments! I love and appreciate them all.

* * *

Chapter III

It took years of careful planning before Sherlock was able to put his dreams of visiting the Shoreline into action. Mycroft had kept an annoyingly close watch on him after the incident in the shipping lanes, probably because Lestrade had informed him of his concerns (the gods protect them all from the overly-conscientious).

For all it was tempting to throw caution to the winds and simply swim away, it wouldn't do to risk the humiliation of having one of Mycroft's agents following him and bringing him back.

An opportunity finally arose when Sherlock was sixteen years old. Irene had contracted a fever which freed Sherlock from his lessons for a while, and Mycroft was busier than usual tending to trade disputes in the Eastern quarter of the Queendom. At last Sherlock had a window of time when he could count on his movements being relatively unobserved and unremarked upon.

Sherlock packed for his expedition with great care, making sure to be discreet in his acquisition of supplies (rope, knives, map). He left in the early morning, a note on his bed informing the curious (Mycroft's spies) that he had gone to stay with Una. It was a believable lie – Sherlock already spent most of his free time there.

* * *

Sherlock swam a circuitous route out of the city, careful to cut back over his tracks several times to confuse anyone who might be following. Once he was sure he wasn't being followed he turned and headed for the outer regions of the Queendom.

The areas nearest to the Shoreline were noticeably different from the Inner Quarter of Holmes. Seaweed crops started to thin and straggle, fish shoals sparse and more infrequent. The homes Sherlock passed were in a state of disrepair, their inhabitants staring at the passing boy with sullen suspicion.

The map grew unfortunately approximate as he neared the very edge of the Holmes territory and Sherlock was forced to stop and ask directions from a group of teenaged mermaids gathered around a porpoise skeleton.

"You're going to the Shoreline?" A scrawny boy with dark eyes asked him, eyebrows raised.

"Not exactly." Sherlock said, choking down his irritation. "Just need to be certain of its exact location."

"I could take you there if you want." The boy smiled at him, in a way that made a faint alarm ring in Sherlock's mind. What did the boy want? And then the boy's grin grew softer and shyer, eyes flicking briefly down to Sherlock's torso.

Oh. Sexual interest. Dull.

"Not necessary." Sherlock said. "If you'll just point me in the right direction…"

"Of course." The boy lowered his eyelids in a way that was obviously intended to be appealing. "If you head East until you reach the Sunken Anchor and then head North again you should reach the Shoreline within the hour. It's a dangerous route, though. I do hope you'll be careful." The boy's eyes were wide with apparent concern.

"I'll be perfectly fine, I assure you." Sherlock said.

"If you change your mind about the tour," the boy says, "You can always some and find me again. The name's Jimisa, you can ask anyone around here, they'll know where I am."'

"Of course," Sherlock said curtly and swam off.

The scrawny boy's instructions proved valid and Sherlock found himself spying land within an hour. He approached the shoreline with cautious fascination, noting the Human debris that littered the water with increasing frequency. The water grew shallower. Sherlock could see a sandy expanse rising up out of the water ahead of him. It was empty – no Humans in sight – but there were traces of their activity everywhere. A wooden slat ran from between the stones of the beach under the water. Sherlock followed its path with interest. He was getting close now, the water dangerously shallow. The tide pulled him forward, a persuasive motion, threatening to beach him. He ought to turn back, get some distance.

But then he spotted something caught in a clump of sea grass a few feet away from the edge of the water. A small box-like shape, with leaves that ruffled in the wind. Sherlock remembered what Una told him about Human scrolls. Could this be a proper Book? One undamaged by contact with the sea? If he could preserve it, and read it – just think of what he could learn about Humanity….

Holding his body very straight, Sherlock swam through the shallow waters. A bank of sand brushed against his chest he pulled himself out of the water and up along the beach, reaching out for the book.

It was hard to manoeuvre himself out of the water – his tail seemed to drag at his momentum like an anchor. The sand underneath him felt soft and slightly warm, clinging uncomfortably to his skin as he moved. Frowning Sherlock pulled himself forward into the softer patch of sand by the grass, and at last his hand closed around the book.

_The Lost World_, he read. The pages, thinner in texture than Mermaid scrolls, felt unbelievably dry to his touch. He peered at the densely set black text in fascination. Already he could see that the examination of this text would take him hours. Casting a quick preservation spell on the paper, he tucked the book into his belt and turned to haul himself back towards the sea.

Except that he found he couldn't move. Sherlock stared down at his tail – somehow it had sunk several inches into the soft sand around, the end of it had completely disappeared. Sherlock jerked sharply, trying to pull it free and he felt the ground between him lurch. Sherlock stared in disbelief as the sand beneath him shifted, swallowing his lower portions almost completely.

Sherlock began to feel panic prickle along his spine. Clearly there was something very wrong with this place: the ground beneath him was not solid as had thought, but some kind of half liquid pit apparently intent on absorbing whatever solid objects came its way – and movement appeared to worsen the situation. Carefully Sherlock attempted a smaller gentler shift in his posture. As he had suspected, the sands around him only shifted further, pulling him slowly downward.

Could a person swim in what was effectively a thickened soup of earth? Sherlock suspected not. In fact he suspected the consequences of being pulled further into this sand-water would result in his slow suffocation and death.

He was several miles away from the nearest Mermaid settlements. Were he able to call up the requisite magical power needed to send a Summons for help it was unlikely anyone would respond in time.

A prickling chill around his midriff assured him that the sand pool was closing around his waist. There was really no other option at all.

Sherlock took a deep steadying breath, and opened his mouth wide, calling in Human. "Help! Help!"

The words seemed to melt into the sea damp air. Nothing responded.

"Help! Please! _Help me_."

Sherlock must have shouted too enthusiastically because the sand beneath him lurched again and he was suddenly submerged up to the bottom of his rib cage. Sherlock shut his eyes briefly, forcing himself to be calm. Opening them against he shouted as loud as he could without risking too much movement.

"Help!"

The words echoed into silence, but only for a moment. Sherlock's keen hearing began to pick something up, a slap-slap, the sound of something moving over wet sand. Something appeared on the horizon of the nearest sandbank. A human face staring down at him, wide eyed.

"Shit!" A voice called out. And then. "Don't move!"

Sherlock let out a breath of mingled relief and irritation at the painfully obvious advice. The human was descending the sandbank with more haste than judgement, feet slipping in the soft drifts. Sherlock was glad to see that unlike Sherlock, the Human didn't appear to be sinking into it.

The Human stopped a few feet away from him, blinking as if trying to assess the situation. Sherlock was about to snap at him to get on and do something, when the Human jerked into movement, grabbing hold of the belt around his waist, and tugging it out of the garment in which it was looped.

"Hold onto this." The Human said, and flung the metal clasped end of the belt to him. Sherlock grasped hold of the end with both hands. The Human pulled hard at the other end and Sherlock felt himself slowly begin to lift out of the sucking depths of the sand.

"Easy," The Human said in a soothing tone, whether to Sherlock or himself Sherlock wasn't sure, and pulled again. Sherlock hooked his fingers through the metal clasp, holding on as tight as he could. It was no good, however. Sherlock could see the stitches on the seam attaching the clasp to the leather straining. He opened his mouth to warn the Human but it was too late. With a jerk, the stitching broke and suddenly Sherlock was holding a piece of metal with a piece of broken leather attached. He fell back, hard, and felt the pit yawn beneath him, cold sand closing around his neck.

"Keep your arms up! Reach up!" The Human sounded more than a little frantic now. Sherlock opened his eyes to see him again attacking his own clothing. He pulled off the upper garment which had been swathing his chest and arms.

"Catch hold of this." The Human said, tossing the arm of the garment to him. Sherlock missed the first throw which caused a burst of swearwords from the Human but he caught hold of it the second time. Carefully he wrapped in once around his wrist before nodding at the Human who tugged hard. Once more Sherlock felt himself slowly lifting out of the clinging sand.

The Human was pulling hard, face reddening, but to Sherlock's gratification didn't pause for second as Sherlock inched further and further out of the mire. Finally, with a last jerk of the garment and a sucking pop from the grasping sands, Sherlock found himself pulled free, falling headfirst onto a blessedly solid bank of sand at the Human's feet.

The Human made an incoherent sound, and doubled over, gasping.

"Bloody – bloody hell."

Sherlock carefully pulled himself straight taking deep breaths of sand free air.

"Are you all right?"

"I – I believe so." Sherlock automatically glanced down at himself to check – he was coated in sand but otherwise intact.

The Human laughed a little, and looked up. "That - that was completely insa-"

The Human stopped halfway through the word, mouth falling open.

Ah. Sherlock glanced down at his sand encrusted tail and back to the Human, whose eyes had taken on a glazed look. Of course. The Human had recognised him for what he was. Sherlock's mind briefly flicked through the stories he had heard, Human's caging Mermaids, hunting them, slicing them up for meat…. Automatically his hand reached for the knife at his belt but it is not longer there – must have been lost to the sand pit.

"What… what is that?" The Human seemed to have regained the capacity for speech.

"What do you think it is?" Sherlock asked.

"Erm it looks like…" The Human began, brushing a hand over his eyes as if he were trying to wipe his vision clean of the unexpected sight. "Is it a costume?"

Sherlock considered. Would the Human believe him if he told him it was?

Too late. The Human had moved closer, reaching out a tentative hand to brush against Sherlock's tail. Sherlock can't help a shifting in surprise at the sensation, warm palm brushing against his scales. The Human made a startled sound, drawing the hand back and looked at Sherlock again, eyes round.

"It's – its real. Isn't it. It's really part of you." the Human stopped, still staring.

"Well…" Sherlock admitted.

"You're a-" the Human, said then stopped.

In spite of the danger he was in Sherlock couldn't help but be a bit fascinated at watching the Human draw its conclusions. He could almost see the struggle written in the creases forming around the Human's eyes, and between his brows, the way his eyes made small stuttering movements looking up and down Sherlock's body. Struggling to comprehend what he must all his life have thought to be impossible.

"A mermaid." The Human said at last. "You're a mermaid? And you – actually exist. Jesus."

"It would appear so." Sherlock said, as coolly as he could manage. The Human sat back on his heels, mouth still a little open.

"That's-"

"Yes?" Sherlock tensed, waiting for the inevitable violent response.

"That's incredible," The Human said, with an expression of such sincerity that Sherlock found himself smiling a little.

The Human shook his head abruptly, as if trying to shake water out of ears. "Sorry I – sorry I. God, You surprised there for a moment." His eyes stilled at last, focusing on Sherlock's arm, which was still bound up with the Human's garment. "Does that hurt?"

The Human reached out a hand to touch the edge of the jumper, making Sherlock flinch reflexively.

The Human held up his hands. "Easy. I just wanted to have a look at your wrist."

"Oh," Sherlock held out the hand which admittedly was a little painful. The Human's hands were gentle but firm, the movements precise and confident. Knowledgable.

"Can you move your fingers all right? Flex your wrist?"

Sherlock tried. Although his wrist smarted, he could move it without difficulty.

"OK – good. I don't think anything is broken, but you probably wrenched it a bit. You'll have some nasty bruises. "

"An acceptable alternative to drowning in sand." Sherlock pointed out.

"I should think so, yeah." The human smiled at him. "You've got to be careful here. There are patched of Sinking Sand all over the place – there are signs but you wouldn't see that from the sea, I guess."

Sherlock looked at the Human boy consideringly. Surpring reaction to a new and threatening species: not hostility but care. Not what one would expect from a Human – or from a Mermaid in such a situation. Unless - the confidence with which he'd touched Sherlock's wrists, the air of knowledge…

"You're a Healer." Sherlock guessed.

The boy blinked again, and grinned. "Well, sort of. I took a first aid course, anyway. And I, um, I do want to study medicine next year. If I pass my exams."

"Interesting,"

The Human's face was close to his now, and with the immediate threat of danger apparently lifted Sherlock decided to study it in earnest. An upturned nose, with a smattering of brown freckles on the bridge. Dark blue eyes, pale lashes. His hair was almost the same colour as his skin, and as the sand around them, a tawny golden colour. He was wearing a thin white garment on his chest, and short blue coloured leg coverings. His skin was unscarred and mostly unlined. A young specimen, then.

Sherlock felt a sudden lightness in his chest. He had a real live Human - right there, at his fingertips.

"What's your name?"

"John. Yours?"

"Sherlock."

The boy repeated it, tongue stumbling over the unfamiliar word. "Suh – Juh - Jerlack."

"Sherlock."

"Suhr-luck."

Sherlock cocked his head, amused. "Close enough."

The boy looked at him, mouth half opening as if to speak, before closing again.

Sherlock arranged his face in a way that he hoped was encouraging. "You have questions."

"_So_many questions."

"As do I," Sherlock said softly. "But you may ask first, if you wish."

The boy frowned for a moment, clearly deep in thought. "Well. OK. Are there a lot of you, mermaids, I mean?"

"According to all calculations out population is smaller than yours." Sherlock said. "But yes. A fair few."

"How come you speak - I mean you do all speak English?"

"Not generally. I made a point of it to learn. Humans interest me very much."

"Do other people know you exist. I mean, I always thought it was just a children's story…."

"As far as I am aware Humanity at large remain unaware of our existence. My kind try to avoid yours, for the most part."

"How come you're here then?"

"I saw something that interested me on the beach. I thought I could take it without being noticed. It was - careless, I suppose."

"Right." John looked thoughtful, digesting this. "Um. What are your questions, then?"

"Oh, I have rather a lot of them."

Sherlock moved a little closer to the human, eyes carefully scanning the Human. It is so different to see one alive and breathing, and close, not bloated and distorted by the sea. Above the waist he was identical to any mermaid - it was easy to see why Humans sometimes mistook Mermaid for potential mates. But then, below the waist….

"Could I examine at you?" he blurted out.

John raised his eyebrows. "Umm... examine me?"

"You've already taken a good look at my tail. I was wondering if you might return the favour. They are as unusual for me, as my tail is for you. And - I've never seen a pair up close." Sherlock threw a pointed look at John's legs.

"Oh." John said. "Well I – I guess that's OK. Go on then."

The boy hesitated for a moment before shifting his position so that Sherlock could look at his legs.

Sherlock gave him what he hoped was a reassuring look before bending his head to inspect them. They were tanned, a deep golden colour, and dotted with fine blonde hairs. The feet were flat underneath, lined like a palm with a faint dusting of sand clinging to the creases in the skin. Sherlock could curl his hand completely around the slim curve of John's instep… it felt warm and smooth under his fingers. He moved his hand slowly upward, savouring in the soft brush of hairs under his hand. He bent to examine the moulded curve of John's knee, the shape of it, like a boat's hull half buried in sand. John's upper leg is thicker, the muscle hard under the smooth layer of skin. John's hand shot out to stop Sherlock's from moving further up his leg, and Sherlock noticed that his face had gone pink. Fascinating.

"Erm, that's enough, I think." He smiled a little sheepishly at Sherlock and Sherlock couldn't help but smile back at him.

"This is amazing, John. I've always wanted a live human to study, in the flesh. And here you are – you really are."

John laughed a little at this. "You're kind of the mad scientist type, aren't you? It's funny. I always thought mermaids were supposed to be-"

"Yes?"

"Well, in all the stories they're sort of vain. Interested in their looks, combing their hair and sitting on rocks, all that."

"Rather a dull lifestyle, I should think."

John grinned. "Yeah."

"It's fascinating the myths one culture develops about another. My people would have me believe you were all ravening monsters, intent on burning up the land and turning the sea black."

"Really?" John looks thoughtful. "I suppose that's not completely wrong. I mean some people are – I imagine if some of them got their hands on you they'd do all kinds of things."

"You mean, put me on show? Lock me in a cage? Kill me and then dissect me?"

"I guess, yeah." John shivered slightly. They sat silently for a while, both deep in thought.

"They got one thing right, the stories about you people, though."John said, and he looked at Sherlock again with that wondering expression in his eyes. "You look like a movie star."

Sherlock looked at him uncomprehendingly.

"Beau – er, handsome." John explained. "Compared to normal human beings, I mean."

For some reason he had started to go pink again.

Sherlock cocked his head to one side. "I am considered attractive by the standards of my kind."

"Right, well you – that explains it."

John was still rather pink, and had taken to rubbing his hand over the back of his neck. "Sorry. This is weird, you know? I've never talked to a mythical creature before. I'm saying all kinds of stupid shit."

"I don't think you have any reason to be embarrassed." Sherlock said slowly. He tried to locate the source of John's discomfort. Was it considered rude in human culture to compliment another's appearance? "Your conversation is far more engaging than most mermaids I encounter. And you haven't broken any social taboos that I am aware of."

John laughed out loud at this. It was a very pleasant sound, and Sherlock found himself leaning closer, hoping to absorb the sound and play it back later.

"Right," said John, "Well, I'm glad of that, at least."

"I am probably better prepared for this conversation. Studying Humans has been my life's work."

John squinted at him. "Yeah? No offense, but you don't look very old."

"I am sixteen years of age." Sherlock said. "I've been studying humans since I was ten. How old are you?"

"Eighteen."

"That's what I would have guessed. Our species don't age too differently, then."

"Guess not. Have you really been studying us since you were ten? That seems –"

There was a sudden buzzing sound from John's pocket, and he leapt to his feet.

"Sorry." He pulled a small oblong from his pocket and held it to his ear.

"Clara?" he said, eyes darting around the beach. "Woah, wait, slow down. Where are you?"

There was a silence, and John frowned, a small line appearing between his eyebrows.

"Are you _serious_? How did she – oh. OK, yeah, I'm coming. Hold tight. I'll be there as soon as I can."

He snapped the oblong box shut, his mouth pulling down at the corners. When he looked back at Sherlock his expression was momentarily surprised as if he had forgotten that Sherlock was there.

"It's a communication device." Sherlock guessed.

"What? Oh, yeah, it's a mobile phone. Look, Sherlock, I've got to go. My sister, she's got herself in some kind of accident. I don't know why she always-" John sucked in his breath in angrily. "Look, do you need help, to get back into the water?"

Sherlock hesitated, cold disappointment welling up in his chest. He'd barely begun his examination. How could he persuade the Human to stay longer?

"I'm still a little hurt." He clutched at his wrist again. "If you could wait a little longer…"

John's face screwed up, his hand clenching and unclenching.

"Oh God. I'm sorry, I really have to go. And I really don't want to leave you stranded here, with the Quicksands so close …."

"Well. If you could help me get a little closer…" Sherlock said, reluctantly.

John nodded, and placed his arm under Sherlock's shoulders. He half lifted half dragged Sherlock over the sand until they reached the water.

"There you are." John placed him down gently in the water. "You'll be all right, from here?"

"Yes," said Sherlock.

"Good. Right." John began to move back slowly.

Sherlock reached out to grab John by the wrist. "I want to see you again. We still have those questions."

John's eyes crinkled slightly at the corners. "I - yes OK, I – _damn_ it." His pocket started buzzing again. "I'll try and be here tomorrow. Same time. Stay in the water this time, I don't want you risking the quicksand again. If only Harry doesn't – oh, hell." John pulled the buzzing box – mobile phone – out of his pocket. "Sorry. I really have to run. It was – nice, meeting you." He gave Sherlock a brief smile, and squeezed his shoulder. Then he turned and walked away, putting the phone to his ear again. Sherlock watched him intently, trying to memorise the exact gait of his walk, the precise timbre of his voice as it sounded over the mess of breaking waves.

* * *

The next day Sherlock arrived at the same place on the beach early in the morning, and waited, hiding in the shallow waves. He waited as the sun rose higher and higher in the sky, blistering the skin on his back, and making his eyes water. He waited until the temperature dropped, and the stars blossomed over the lapping waters.

John didn't return.


	4. Chapter 4

Chapter IV

"Where have you been?" Mycroft was waiting for him at the entrance to the Palace. His arms were folded across his chest and his expression was very cold.

"What business is it of yours?"

"You've missed three banquets at which you were scheduled to Sing. You haven't attended your Siren training in over a week and you've been nowhere to be found. Your skin is as pink as a coral reef. What have you been doing, Sherlock?"

"Nothing," Sherlock said. "It's none of your concern."

"I pay for Irene to teach you, and you behave with this discourtesy…"

"The Governance pays for Irene,"

"I _am_ the Governance, more or less,"

"I'm terribly sorry to have put you out of pocket then,"

"Sherlock. Have you been at the Shoreline?"

"What does it matter if I have?"

"What does it – it is a matter of _national security_. If you'd been seen, if you'd been _caught_ – you aren't even fully trained."

"I know more about Humans than anyone in this miserable Queendom. And I can look after myself."

Mycroft looked at him for a long moment. Sherlock stared back defiantly but in the end found he could not keep it up. He dropped his gaze.

"You have to stop, Sherlock." Mycroft turned away in that coldly dismissive way he had when he knew an argument was won.

Sherlock scowled, his face burning. He knew Mycroft was right. John wasn't coming back. He'd swum the length of the beach from one side to the other and there was no sign of him at all. There was a new ache in Sherlock's chest that has nothing to do with boredom. _There is only one truly beautiful thing in the world, only one thing, and I wasn't allowed to hold on to it for even half an hour._ Mycroft didn't understand. How could he?

* * *

"You've been absent." Irene said when Sherlock entered her chambers the next day.

"I've been busy," Sherlock said. "I do have my own interests, you know."

Irene raised her eyebrows. "I know," she drawled. "Though judging by your face they aren't very satisfying to you."

Sherlock looked away, hating Irene, hating everything.

"Will you Sing to me?" he asked impulsively.

There was a long silence as Irene regarded him. "Why do you want me to do that?"

"I'm bored." Sherlock curled his lip affectedly, deliberately mimicking her careless tone. "It might make me feel better."

There was a short tense silence as Irene stared at him. Sherlock looked away, only to feel a sudden pain in his arm. Irene's hand had closed around it, nails digging into his skin.

"Listen to me," she hissed. "These things that I am teaching you – they are not toys. They are not comforts to lull yourself to sleep at night. They are not here to tend to your emotional ills. Do you understand?"

"Let go of me!"

"Sirens who misuse the Song." Irene said. "Who use it for their own gratification, lose themselves in it. Sooner or later they lose the ability to tell Song from reality and become useless, drooling idiots. Is that what you want?"

"No!" Sherlock said, tugging himself free of her. "Of course not."

Irene looked at him for a long time, eyes blazing in her pale face. "Don't imagine you are too clever to make a mistake," she said.

"For the god's sakes," Sherlock said irritably. "I told you, I won't. I won't ask you again."

Irene looked at him for a long moment and then straightened up, abruptly. "Very well," she said, her usual dispassionate tone of voice resumed. "Shall we continue?"

* * *

Irene and Sherlock spent their next lesson near the surface. Irene made Sherlock Sing to the dolphins, making them arc upwards through the water, jump and swim and turn in a dance of his own devising. Every now and again Irene would stop him, suggest some minor adjustment to pitch or posture. In the end though she simply watched, eyes uncharacteristically wistful.

"You've done well," she said, as two dolphins backflipped gracefully before them, sending sparks of water gleaming through the air.

Sherlock ended the Song, and the dolphins gathered themselves, slowly and a little confusedly, to swim away.

"For your next lesson, I need to take you on a trip." Irene said. "Pack for an overnight stay."

"All right," said Sherlock. "Where are we going?"

Irene looked away from his, gaze steely and expression blank. "We're going to my country," she said. "We're going to Ithillya."

* * *

They swam in silence until they reach the borders of Holmes. Irene spoke quietly to the Guards at the border, gesturing, and though they stared at Sherlock, they let them cross over in peace. The residue of the Black Rain has long since dissipated in the water, although there are places were the seafloor was still coated in pools of black sludge. The seaweed crops were sparse and unhealthy looking and the merpeople seemed leaner and sadder than the residents of Holmes. They watched Sherlock pass with hungry hostile eyes.

"Not much further," Irene told him, with a sharp look that made Sherlock wonder if she knew what he was thinking.

They swam to the edge of a great ridge in the land, a blackened barrier of sea earth. Irene took Sherlock's hand and pulled him upwards to hover above it. Sherlock gasped.

A vast metal body, rusted and gaping lay on its side on the ocean floor. The ground around was strewn with objects and what looked like bones. It was a shipwreck – but Sherlock had never seen one so huge in all his life.

"That's incredible."

"Do you like it?"

"I've never seen anything so – can I go closer?"

"Of course. I can show you around it, if you like."

Irene's voice was oddly distant. Sherlock noted that she had wrapped her arms around herself, as if she was cold.

The wreckage was fantastic. They swam in through an open window and wandered around for a long while, though corridors and rooms, into a vast chamber that felt like a cave, and which still had a huge mass of sculpted glass, looking like a giant sea anemone, slumped in the centre.

"I think this held some kind of light fitting," Sherlock said excitedly. "Look at its placement, right at the centre of the room. And these hooks – it must have been attached to the ceiling."

"Perhaps." Irene agreed, but her expression was still very distant.

"Irene," Sherlock said slowly. "This isn't – it isn't the ship that brought the Black Rain, is it?"

"No," Irene said, smiling tiredly. "That ship was smaller."

"But then why-" Irene turned her back on him, swimming upward. Sherlock followed her out onto the deck of the ship. With the ship towering above them on one side and the great earth Ridge above them Sherlock found himself feeling rather small.

"It doesn't happen often," Irene said, at last, turning towards him. "But one day you may be asked to sink a ship."

Sherlock stared at her for a while, comprehension slowly dawning. "Did _you_ bring this ship down?"

"It was one of my first jobs. It quite made my name, I believe."

Sherlock looked around him in awe. "I should think it would."

"It wasn't as difficult as you would think. I Sang to the captain – he steered them straight into an iceberg. The right angle, the right velocity and you can bring anything down."

"What was it like?" Sherlock asked breathlessly.

"Slow," Irene said. "I watched them for a long time, scampering around on the decks like sea crabs. Some of them escaped in smaller boats. A lot of them didn't."

"Why did you sink it? Were they a threat?"

"Not particularly." Irene sighed. "In those days, we were just starting to get seriously worried about Human activity. They'd started pumping out poisons into the sea at an alarming rate – nothing like the rate they are now, of course, but at the time it seemed like a worrying escalation. And then this great colossal _monster_ of a ship came along, far too big, far too frightening. It was an emblem of everything humans were doing, how fast they were changing things, gobbling up the sea's resources and making it unsafe for Merkind. And so our Governance decided, enough was enough. We had to send a message. We had to sink the ship."

"Not very sensible," Sherlock commented. "How are Humans supposed to understand the message if they don't even know it was sunk by us? They aren't even aware we exist."

"Very good," Irene said, smiling. "I don't think the message was _really_ intended for them."

Sherlock frowned at her, puzzled.

"The party line was that we were sending a message to Humanity but in fact it was out own people that we were trying to reassure. In those days we still believed that we were the superior race. The ones who held the cards. We needed a show of strength to bolster the public opinion."

"I see." Sherlock said.

"Have you ever seen someone drown?" Irene asked, abruptly.

Sherlock shook his head.

"I hadn't either, before that night. But I watched them – I swam through their midst. I'd never seen so many Humans at once and all of them were dying." She has turned away from Sherlock now, eyes gazing into the middle distance. "You know how you feel, when a Song ends?"

Sherlock nodded.

"There's this energy flooding through you, you feel - powerful. And that Song, Sherlock, I'd never sung anything so potent, so perfect. And then watching them – _struggling_ like that. Men and women and children - their eyes wide and their arms stretching upwards, reaching out, just begging for help. It was – beautiful. And it was terrible. It was the most terrible thing I've ever seen. I still have dreams about it. I see their faces when I close my eyes."

Sherlock closed his eyes and tried to imagine it – unwittingly his mind conjured John's face. Blue eyes and the smell of sand, the feeling of muscle shifting under smooth skin. Sherlock opened his eyes very fast."Do you regret it?"

"I don't think I do. The year before it happened a cousin of mine had been playing near the surface. She managed to get herself caught on a fishing hook – it tore her up pretty badly. And then the Humans, the fisherman, pulled her out of the water they tried to club her into submission. She escaped them, in the end, but she wasn't the same. And then later, when the Black Rains came… This _is_ a war, Sherlock, even if _they_ aren't aware of it."

"I don't know if I could do it."

"You might have to," Irene said "to protect your country. Your people."

"I don't want to."

"Nobody wants to. We do what we have to do."

They stayed for a long while in silence, looking up at the broken hulk of the ship. Eventually Irene breathed out a sigh, and pulled herself up through the water "Come on." She said, and took Sherlock's hand. "Time to get you home."

* * *

A little while later, Irene told Sherlock that she was leaving.

"I don't have anything more to teach you."

Sherlock watched the dolphins they had been Singing to zig zagging drunkenly through the water. They were still feeling the effects of Sherlock's last notes.

"I've still never Sung to a ship," Sherlock said. "I don't know if it will work."

"If you can do that to a dolphin, you can handle a human." Irene said. "Humans are far more susceptible."

Sherlock thought about it. He couldn't explain the unhappiness that welled up like freezing water in his chest. Sometimes he wasn't sure if he loved or hated his teacher, but she was one of the only people in this place with brains. One of the only few capable of understanding him, and who sometimes seemed to like him.

"Stay," he found himself staying. "I'd - I'd like to have you with me."

Irene shook her head decisively. "You don't _need_ me."

Irene swam closer to Sherlock, cupping his face in her hands. Soft, Sherlock thought, and cruel.

"I'll miss you too."

Her eyes were lovely, Sherlock thought, a clear steely blue. Irene leaned forward abruptly and pressed her mouth to his. It felt soft and warm. Sherlock reached out his arms tentatively, brushing the sides of her slim body with the tips of his fingers, and he felt her shiver. Then she pulled away.

"Remember me, won't you?" Her voice was cold again, ironic. Sherlock doubted anyone had ever forgotten Irene. He nodded wordlessly.

"Good luck, Sherlock of Holmes," Irene said, quietly. Sherlock watched her numbly as she swam away. She did not look back.

* * *

After Irene left, life settled into a dull sort of pattern. Now officially the Queendom's only Siren Sherlock found himself much in demand. Lestrade and his team called him in frequently for analysis and, more rarely, to divert ships. Mycroft also insisted Sherlock take on other clients – farmers with particularly troublesome seal herds for example, or aggressive dolphin pods. Once or twice he was called in by the Criminal Guard, to help persuade suspects to tell the truth. This was a little more interesting, although Sherlock found himself disappointed by how often the Criminal Guards seemed to have missed the obvious.

After a certain incident when Sherlock informed the chief Sentinel that he wouldn't _need_ to use a Siren if he only would only use his pouchy little eyes, it was hastily decided that all further Criminal cases requiring Sherlock's assistance would be channelled through Lestrade. Apparently they 'knew how to handle him', which was news to Sherlock but didn't really mind. The fewer morons he had to deal with the better.

Living in the Palace had become insufferable. Siren training appeared to have dialled up some of Sherlock's sensitivities, or maybe it was simply the transition to adulthood. Either way he had begun to find the idle chatter and idiotic pastimes of the members of Court to be painful to the point of being unbearable. Becoming a Siren had meant courtiers and common people alike seeking him out for help with their trivial problems, and even worse, trying to involve him in their social pursuits.

After two years of near constant irritation Sherlock was finally able to persuade Mycroft to him let Sherlock move out of his rooms in the Palace and into the cave above Una's. At least his contact with other mermaids was limited there, and he had the benefit of Una's cooking.

Sherlock's boredom, however, remained apparently unquenchable. Only when his mind was occupied with Human matters did the gaping emptiness in Sherlock's chest ease up a little. Sometimes he thought about visiting the Shoreline again. But then he remembered the empty beach and the horrible quiet and decided that it would be of limited benefit anyway.

One day when he was alone in his new Cave after a particularly tiresome day persuading orcas not to attack the Queendom's seal stock, Sherlock contemplated the idea of Singing to himself.

_You'll lose yourself, _Irene had said.

Somehow that didn't seem like a completely terrible idea. He lay back in his hammock, and hummed a few brief notes imagining them echoing back and absorbing themselves into his skin. Sherlock found himself shivering with the sudden flush of warmth that overtook him. Suddenly the world seemed _interesting_ again, his mind feeling not as it had, like a dulled scythe slicing away at the same old crop, but sharp and glittering again. He found himself wanting to go the the Warehouse again, to sift through the Findings. This time he was _sure_ he would have an epiphany.

Sherlock let the notes die out. The feeling they had brought faded slowly, but left him with a slightly renewed sensation of clarity. Perhaps, Sherlock thought, it wouldn't be such a terrible idea to Sing to himself from time to time. Irene was far enough away that she would never know about it. And he had enough self control to stop himself before he went in too deep. Anything was better than living in this permanent state of dullness.

Also Mycroft would pitch a fit if he knew. Somehow that thought was deeply cheering.

* * *

Sherlock kept Singing to himself, and nobody seemed to notice. Lestrade frowned at him a few times when he turned up to the Warehouse with a wide smile on his face, and Una sometimes looked at him with worried eyes but neither seemed able to pinpoint the source of their anxiety about him. If they did they never mentioned it. The years passed and the Singing became an indispensible part of his routine. Sherlock wasn't sure how he could ever have managed without it.

* * *

"Your Highness,"

Sherlock glanced up from the Human garment he'd been examining.

Lestrade was standing in front of him, face grim. "We need your help. A ship has strayed out of the Lanes, and it is heading for the tuna spawning ground."

Sherlock pulled himself up slowly, taking in the unusual tension in Lestrade's shoulders. "Large ship, is it?"

"Big as I've ever seen one." Lestrade said tightly.

"Has anyone ever told you that you worry far too much?" Sherlock said. "I'll deal with it. Easily."

* * *

It was dark by the time they reached the surface, a cold wind whipping over the lurching waves, and pushing scraps of cloud across the moon. The ship was indeed bigger than anything Sherlock has seen before, a great dense weight resting on the water. As Sherlock began his Song he could sense a proliferation of Human bodies and minds, packed close together, brimming with excitement and purpose. In the hold his song clattered and reverberated against a vast collection of large metal objects. The way the ship was thickly built, from reinforced metal, made it difficult for the Song to pierce though, as if it had been designed to withstand more than water and song. Sherlock halted his song for a moment, eyes wide.

"Lestrade!" he said. "I think it's a military vessel."

Lestrade did not seem to find this news nearly as exciting as Sherlock did. If anything the tension on his shoulders increased, eyes narrowing.

"Carry on Singing," he said.

Sherlock did, trying hard to feel out the contents of the ship as he did. It had been a long time since a military endeavour had been spotted near Holmes. They had very little evidence of Human weaponry in recent years and Sherlock was sure their technology would have progressed, much as everything else about Humanity had.

Sherlock could feel the Captain now, one dull little mind among many, suddenly feeling a surge of confusion about the direction he was taking the ship in.

_That's right_, Sherlock thought impatiently at him, _turn around_. _You know there's a better route._ The Ship began to slow down, turning slowly in the water. Sherlock turned his mind back to mapping out the layout of the ship. Men in the hold below, crammed close, a dozen metal objects and…..

For a moment Sherlock felt something completely unexpected. The Song had hit up against something - familiar. The shape of the notes breathed back to Sherlock called to mind a face that Sherlock had never forgotten, dark blue eyes and laughter…. Impossible. Sherlock let out another long note, focussing hard on the dawning point of recognition.

_Not impossible_, he reminded himself. _Just very very improbable._

Sherlock turned all the song's energies towards the presence that was increasingly beginning to burn in the corner of his mind, the warmth of familiarity becoming a blazing heat. _Come out onto the deck, _he sang to him. _I need to see your face._

Sherlock felt the Human mind stutter at the sudden onslaught of Song, a brief reflexive resistance giving way to warm acquiescence. The Human was moving upwards, stepping out onto the deck. Around him the wind whipped hard across the water, huge waves tipping the massive ship back and forth. Sherlock ignored it all, eyed fixed on the deck. A small figure had stepped out, and seemed to be looking around itself, lean shape silhouetted in the moonlight.

_Come closer to me. Face the light. _The human obeyed and Sherlock found the Song dying on his lips. The face looking down at him with a dazed frown was still distant but close enough to be unmistakable.

John appeared to have spotted him too. At any rate his mouth fell open, and he clambered up onto the rails of the ship, peering down into the water as if to get a better look.

Distantly Sherlock heard Lestrade shouting at him to 'for the god's sakes, keep Singing.'. Sherlock blinked, and opened his mouth again, but it was too late: somewhere deep inside the ship the Captain's mind snapped free of the song, and abruptly realised that his Ship was veering off course. A shock ran through the ship as the Captain pulled hard on the guiding wheel, turning the ship sharply. Sherlock saw John stagger at the sudden movement, arms flung out. He regained his balance briefly only for a second jolt, this time from the ship cresting head on into one of the larger waves, to throw him off his feet.

Sherlock watched in appalled silence as John fell, head striking at the side of the ship before plummeting like a stone into the dark water.


End file.
